I adjusted the pineapple juice down to 2 oz and got rid of the simple syrup (my pineapple juice is sweet enough as is). With that mix there is a fine balance between the Campari, the lime juice, and the rum. I have also sucessfully substituted Lemon Hart 151 for the Blackstrap. (You need a strong flavored rum for a good balance). Wray & Nephew and Cruzan 151 are not optimal choices for this drink.

I highly recommend following Sam Ross' lead and decreasing the pineapple juice to 1 1/2 oz. At that ratio it's a sensational drink. A collection of extreme flavors that don't sit in a conventional "balance" so much as they complement and magnify each other. Extraordinary.

As much as I love it, I don't recommend Smith & Cross for this drink at least on its own; you want the deep molasses notes from the Black Strap, or barring that mix a dark Jamaican like Coruba or Meyer's with a dash or two of Angostura or chocolate bitters. A S&C float might not be out of place. Simple may or may not be needed, depending on the tartness of your juices, the sweetness of your rum, and your own taste.

A slight recipe tweak developed by Giuseppe Gonzalez of Painkiller (NYC) and that can be currently found on the menu at Milk & Honey NYC (thanks to head barman Theo Lieberman), has a dash more Campari (.75) and much less pineapple juice (.5) -- making rum and Campari the dominant flavours, a more bitter and alcoholic drink (also heavily reliant on the quality of the pineapple juice). It's the best variation I've tasted. <a href="http://www.nytimes.com/2014/04/09/dining/a-bird-walks-into-a-bar.html?_r... NYT piece explains it</a>.